Magnetic resonance imaging (MRI) is an imaging technology involving biomagnetics and nuclear spin that has advanced rapidly with the development of computer technology, electronic circuit technology and superconductor technology. MRI uses a magnetic field and radio frequency (RF) pulses to induce nutation of processing hydrogen nuclei (i.e., H+) in human tissue to generate RF signals that are processed by a computer to form an image. If an object is placed in a magnetic field and irradiated by suitable electromagnetic waves to produce resonance therein, and electromagnetic waves released thereby are then analyzed, the positions and types of the atomic nuclei of which the object is composed may be learned. On this basis, a precise three-dimensional image of the interior of the object may be drawn. For example, a moving picture of contiguous slices may be obtained by performing an MRI scan of the human brain, starting at the crown and continuing all the way to the base.
In an MRI system, an RF phased array coil is a commonly used type of RF receiving coil. An RF phased array coil includes multiple surface coils, with each surface coil being embodied as an antenna unit. Mutual inductive coupling exists between any two antenna units that are close to each other. By performing decoupling between antenna units, the associated resistance between antenna units may be reduced, in order to reduce associated noise and increase the reception signal-to-noise (SNR) ratio of the RF phased array coil.
In the prior art, methods for decoupling between antenna units may include inductive decoupling, capacitive decoupling, overlap decoupling and low-noise preamplifier decoupling, etc. Inductive decoupling may employ a solenoid formed by coaxially interwoven or adjacent inductive coils wound from spiral wires.
However, as the number of RF coil channels has steadily increased, the coil structures have become ever more complex. Decoupling inductors formed from windings deform easily and do not lend themselves to mass production.